A hydraulic machine of the prior art comprises a paddle wheel and a ring gate to control the supply of water for the paddle wheel. The ring gate can move between an open position and a blockage position of a water supply channel for the ring gate. The movement of the ring gate between its open and blockage positions is controlled by an electrohydraulic control device.
A control device of the prior art includes dual-action hydraulic cylinders each comprising a rod and a piston that separates two chambers adapted to receive an actuating fluid of the cylinder. Such a control device also requires mechanical components to synchronize the movements of the cylinder pistons. In particular, among the mechanical components associated with each cylinder, a reversible screw-nut pair converts the translation of the piston and the rod into rotation of a pinion outside the cylinder. Furthermore, a transmission chain connects the pinions to one another so as to synchronize their rotations and subsequently synchronize the translations of the pistons of the different cylinders.
However, this control device comprises several mechanical components for each cylinder that require delicate adjustments and tedious maintenance operations.